Over the years I have come to the realization that Kira is more or less my favorite character on that show. I love all of them (except maybe Worf, who was always kinda meh), but Kira-centric episodes, scenes and arcs tend to be the ones I love most about this show. I'm a huge fan of the Bajoran arc in the first two seasons and Kira is all over that. She's such a strong and at the same time very conflicted and often vulnerable character. Plus, Nana Visitor does a wonderful job portraying her.
Sure, I like Ro, too. But don't anyone get near my Major Kira!